The present invention relates to a bicycle electricity generator and a method of attaching the electricity generator to a bicycle.
A bicycle is usually equipped with an electricity generator which generates electricity by rotating a bicycle wheel so as to supply the electricity to a lighting device. Japanese Patent Application Laid-open No. 63-502652 and Japanese Utility Model Publication No. 1-23900 have disclosed a bicycle electricity generator which is attached to the axle of a bicycle wheel.
A conventional bicycle electricity generator, which is disclosed in Japanese Patent Application Laid-open No. 63-502652, comprises a stator mainly consisting of a coil, and a rotor mainly consisting of a magnet, both of which are combined together by means of a bearing. In more detail, the stator is fixed on a fork of a bicycle, whilst the rotor is fixed onto spoke members of a bicycle wheel. While the bicycle is running, the rotation of a bicycle wheel will cause the rotor to rotate, thereby enabling the generator to produce electricity.
Another conventional bicycle electricity generator, which is disclosed in Japanese Utility Model Publication No. 1-23900, also comprises a stator and a rotor, both of which are combined together by means of a bearing. In more detail, the stator is fixed on the axle of a bicycle wheel, whilst the rotor is fixed on a hub which is freely rotatable with respect to the wheel axle and holds a number of spokes. While the bicycle is running, the rotation of a hub will cause the rotor to rotate, thereby enabling the generator to produce electricity.
However, in the bicycle electricity generator disclosed in Japanese Patent Application Laid-open No. 63-502652, since the rotor is fixed onto spoke members (thin wire-like members) of a bicycle wheel, there is only a low strength in the fixation of the rotor, resulting in a problem that the rotor is apt to fall off the spoke members.
On the other hand, in the bicycle electricity generator disclosed in Japanese Utility Model Publication No. 1-23900, although the rotor is fixed on a hub, sometimes this kind of fixation is difficult because of the particular specifications of bicycles different. For instance, the distance between a hub and a fork will be different in different types of bicycles. In some extreme cases, a distance between a hub and a fork is too small or too large, making it impossible for a bicycle electricity generator to be installed on the axle of a bicycle wheel.